Mobile devices, such as smartphones, now allow users to perform a variety of tasks that traditionally required different types of devices. For example, a user may be able to use different client applications executable at the same mobile device to browse online content, play audio files, capture digital images, view directions for navigating between different locations or points of interest, and exchange messages between other users or computing devices via a mobile communication network. A user may also download and install various third-party client applications at the user's mobile device for viewing information and content related to general topics of interest. An application developer or affiliated service provider may use such a client application to provide different services to the user. Such services may include messaging services to which the user may subscribe in order to receive, for example, real-time message notifications or breaking news alerts at the user's mobile device. The message notifications or alerts that are sent (or “pushed”) by a service provider for a particular client application may be displayed within a general notifications window via a user interface of the operating system at the user's mobile device, even though the client application may be closed or may not be actively executing at the mobile device when such notifications are received.
In addition to the message notifications or alerts provided by a service provider associated with the client application, third-party content providers may use the client application to deliver targeted content (e.g., advertisements) to the user at the mobile device. In contrast with the aforementioned message notifications that may be displayed within a general notifications window of the operating system's user interface, the targeted content from a third-party content provider is typically displayed within a dedicated portion of a user interface of the client application itself while it executes at the mobile device. An example of such targeted content may include, but is not limited to, an advertisement displayed within a pop-up window for a webpage loaded within a mobile web browser. Thus, conventional solutions for delivering targeted content to a user's mobile device typically require the client application to be open or actively executing at the mobile device in order for the content to be displayed to the user at the mobile device.